Beginning Point of the U.S. Public Land Survey
The Beginning Point of the U.S. Public Land Survey is the point from which the United States in 1786 began the formal survey of the lands known then as the Northwest Territory, now making up all of Ohio, Indiana, Illinois, Michigan, Wisconsin, and part of Minnesota. The survey is claimed to be the first major cadastral survey undertaken by any nation.
Source: Wikipedia — Beginning Point of the U.S. Public Land Survey (CC BY-SA 4.0)